A battery-powered device such as a power tool can be used cordlessly, for example, at a construction site, when a detachable battery pack containing rechargeable batteries is provided. When the battery pack in the battery-powered device is removable, the removable battery pack can be repeatedly recharged and reused. When the remaining capacity of a battery pack is low, the battery pack can be placed in a battery pack charger and recharged.
An example of such a battery pack is shown in FIG. 31 through FIG. 33. FIG. 31 is a perspective view showing a battery pack 30X of the prior art installed in a battery pack charger. FIG. 32 is a perspective view showing a battery pack 30X of the prior art installed in a power tool PT. FIG. 33 is a perspective view of the battery pack 30X in FIG. 31. A battery pack 30X with very little remaining capacity is placed in a battery pack charger 100 as shown in FIG. 31 and then recharged. When the charging has been completed, the battery pack is removed from the battery pack charger 100 and placed in a power tool PT as shown in FIG. 32 to provide power. Here, the battery pack 30X is detachably mounted in the battery pack charger 100 and the power tool PT. For this, as shown in the perspective view of FIG. 33, the battery pack 30X has an engaging hook 54X and a detachment unit 52X. The engaging hook 54X keeps the battery pack 30X from detaching when it has been attached to a battery pack charger or power tool PT. In the battery pack charger 100 in FIG. 31 and the power tool PT in FIG. 32, an engaging recess 17X is formed to engage the engaging hook 54X in a position corresponding to the engaging hook 54X in the attached battery pack 30X. In the example shown in FIG. 33, the engaging hook 54X is biased so as to protrude downward from the battery pack 30X. In this way, the engaging hook 54X on a battery pack 30X set in the battery pack charger 100 in FIG. 31 or the power tool PT in FIG. 32 is engaged in the engaging recess 17X and secured.
The engaging hook 54X is linked to the detachment unit 52X, and the user manually lifts up the detachment unit 52X to retract the detachment unit 52X into the battery pack 30X in the housing direction. A recess is provided in the detachment unit 52X to make it easier for the user to operate. When the user manually operates the detachment unit 52X, the biased engaging hook 54X is pushed out in the protruding direction from the battery pack 30X. In this way, the engaging hook 54X keeps the battery pack 30X from coming out when attached to a battery pack charger 100 or power tool PT.
It also establishes an electrical connection to supply power from the battery pack to a battery-operated device and exchange various types of signals when the battery pack is mounted in a battery-operated device. An electrical connection is usually achieved by inserting and clamping an electrical contact such as a connector or external connection terminal to maintain a connection.
In a structure for mounting a battery pack in a battery-powered device, an electrical connection has to be established when the battery pack is physically and mechanically mounted in the battery-operated device. The mechanical connection structure can be an engaging hook provided in a latching unit, and the electrical connection can be performed via a connector or external connection terminal. Separating the mechanical connection structure from the electrical connection structure can improve the mechanical connection strength while also improving the stability and reliability of the electrical connection.
For example, see Japanese Laid-open Patent Application No. 2008-236882; and Japanese Laid-open Patent Application No. 2004-236450.